This invention relates to dispensers for tape or other ribbon like material. More particularly it relates to dispensers which include means for advancement of the dispensed material as well as integrally formed cut-off means.
Various forms of resilient elastomeric tape are in common usage. One such tape is unsintered polytetrafluoroethylene tape sold under the trade-mark "Teflon" by duPont de Nemours Company, Wilmington, Delaware. Such tape may be a few thousandths of an inch in thickness. It is particularly suitable for sealing threaded joints of pipe or conduit. It posesses a very low modulus of elasticity and is difficult to tear or rip. Other forms of tape possessing similar characteristics include electrical and surgical tapes formed of polomeric hydrocarbons.
Tape dispensers have been utilized in the past to dispense cut lengths of tape of the type described above. Examples of such prior dispensers are disclosed in U.S. Pat. Nos. 3,050,853; 3,067,514; 3,102,671; and 3,470,781.
In each of the above prior dispensers metal components are utilized in the cutting mechanism which severs the tape strip.
In some of the prior designs the metal cutting mechanism attached to the tape dispenser is extremely complicated and comprises a relatively expensive element. Because of the properties of the tape being severed, these cutting elements are substantially more involved than warranted for the purpose served.
In others such as that shown in U.S. Pat. No. 3,102,621 it is necessary that a razor sharp cutting edge be maintained to accomplish cutting of the tape strip. Once the edge is lost, the cutting mechanism is ineffective.
It is the principal object of the present invention to provide an improved type of tape dispenser for tape of low elastic modulus which includes means for advancement of the tape and which includes integrally formed shearing means to provide scissors-like shearing action to sever the tape strip.